Engineered receptor/ligand system for delivery of therapeutic agents

Abstract

Provided herein are compositions and methods related to targeted delivery of a therapeutic or diagnostic agent to a subject utilizing an engineered receptor-ligand system, such as an engineered dockerin-cohesin system. As described herein, previously-developed targeted delivery systems for delivering therapeutic and diagnostic agents to a tissue of interest have drawbacks that have not been addressed to date. For example, with respect to the blood-brain barrier (BBB) and the blood-cerebrospinal fluid barrier (BCSFB), both of which hamper delivery of agents to the brain, others have relied on the use of endogenously expressed receptors, like the transferrin receptor, to assist the agent across the barriers.

1 - 24 . (canceled) 
     
     
         25 . A recombinant adeno-associated virus (rAAV) particle comprising a nucleic acid containing a promoter sequence and a sequence that encodes a receptor having a ligand-binding domain of a non-mammalian protein. 
     
     
         26 . The rAAV particle of  claim 25 , wherein the receptor comprises at least one domain selected from an intracellular domain, transmembrane domain and extracellular domain of a mammalian receptor. 
     
     
         27 . The rAAV particle of  claim 26 , wherein the at least one domain is a transferrin receptor or nerve growth factor receptor intracellular, transmembrane or extracellular domain. 
     
     
         28 . The rAAV particle of  claim 25 , wherein the non-mammalian protein is a bacterial protein. 
     
     
         29 . The rAAV particle of  claim 25 , wherein the ligand-binding domain is a cohesin domain. 
     
     
         30 . The rAAV particle of  claim 25 , wherein the promoter sequence is a tissue-specific promoter sequence. 
     
     
         31 . The rAAV particle of  claim 25 , wherein the ligand-binding domain binds to a dockerin domain. 
     
     
         32 . The rAAV particle of  claim 30 , wherein the tissue-specific promoter sequence is selected from a Glial fibrillary acidic protein (GFAP) promoter sequence, an Mb promoter sequence, an OG-2 promoter sequence, an SP-B promoter sequence, an SYN1 promoter sequence, a CD14 promoter sequence, a CD43 promoter sequence, a CD45 promoter sequence, a CD68 promoter sequence, a Desmin promoter sequence, an Elastase-1 promoter sequence, an Endoglin promoter sequence, a Fibronectin promoter sequence, an Flt-1 promoter sequence, a GPIIb promoter sequence, an ICAM-2 promoter sequence, a Mouse IFN-β promoter sequence, a NphsI promoter sequence, a WASP promoter sequence, an SV40/bAlb promoter sequence, an SV40/hAlb promoter sequence, an SV40/CD43 promoter sequence, an SV40/CD45 promoter sequence, and an NSE/RU5′ promoter sequence. 
     
     
         33 . The rAAV particle of  claim 30 , wherein the tissue-specific promoter sequence is selected from a GFAP sequence, an SYN1 promoter sequence, an Endoglin promoter sequence, an Flt-1 promoter sequence, an ICAM-2 promoter sequence, a NphsI promoter sequence, and an NSE/RU5′ promoter sequence. 
     
     
         34 . The rAAV particle of  claim 25 , wherein the promoter sequence is selected from an FerL/RU5′ promoter sequence, an FerH/RU5′ promoter sequence, a βAct/RU5′ promoter sequence, an EF1/RU5′ promoter sequence, a CMV/FerL/chEF1 promoter sequence, an SV40/hFerH/mEF1 promoter sequence, and a hybrid CMV-β actin promoter sequence. 
     
     
         33 . The rAAV particle of  claim 25 , wherein the rAAV particle is an rAAV1, rAAV4 or rAAV9 serotype particle. 
     
     
         34 . The rAAV particle of  claim 25 , wherein the nucleic acid further comprises one or more additional sequences that facilitate expression of the receptor and is operatively linked to the sequence that encodes the receptor. 
     
     
         35 . The rAAV particle of  claim 34 , wherein the one or more additional sequences are selected from the group consisting of promoters, insulators, silencers, response elements, introns, enhancers, initiation sites, termination signals, and poly(A) tails. 
     
     
         36 . The rAAV particle of  claim 25 , wherein the nucleic acid comprises one or more inverted terminal repeat (ITR) sequences. 
     
     
         37 . The rAAV particle of  claim 36 , wherein the ITR sequences are modified or derived from AAV2 ITR sequences. 
     
     
         38 . The rAAV particle of  claim 29 , wherein the cohesin domain is a cohesin 7 domain. 
     
     
         39 . The rAAV particle of  claim 25 , wherein the receptor comprises a transferrin receptor domain fused to a cohesin domain. 
     
     
         40 . A composition comprising the rAAV particle of  claim 29  and a pharmaceutically acceptable carrier. 
     
     
         41 . A method of treating a mammalian subject suffering from a disease or disorder comprising administering the composition of  claim 40 .